Electron Affinity
Electron Affinity - Related Videos
03:07
Electron Affinity
0 Views •
2020
The electron affinity (EA) is the energy change for adding an electron to a gaseous atom to form an anion (negative ion). This process can be either endothermic or exothermic, depending on the element. Many of these elements have negative values of EA, which means that energy is released when the gaseous atom accepts an electron. However, for some elements, energy is required for the atom to become negatively charged, and the value of their EA is positive. Just as with ionization energy,...
01:41
Affinity and Avidity
0 Views •
2019
Overview Antibodies bind to toxins or substances on the surface of cells, bacteria, viruses, or fungi. The substance is called an antigen, and the precise binding site is the epitope. The strength of the antibody-epitope interaction is called affinity. When an antibody binds an antigen by multiple epitopes, the cumulative strength of the interaction is called avidity. The strength of the interaction influences the elicited immune response. The Adaptive Immune System Increases Efficiency by...
04:51
Streptavidin-Affinity Grid Fabrication for Cryo-Electron Microscopy Sample Preparation
0 Views •
Cited by 15 •
2023
A step-by-step protocol for fabricating streptavidin affinity grids is provided for use in structural studies of challenging macromolecular samples by cryo-electron microscopy.
02:48
Ionic Bonding and Electron Transfer
0 Views •
2020
Ions are atoms or molecules bearing an electrical charge. A cation (a positive ion) forms when a neutral atom loses one or more electrons from its valence shell, and an anion (a negative ion) forms when a neutral atom gains one or more electrons in its valence shell. Compounds composed of ions are called ionic compounds (or salts), and their constituent ions are held together by ionic bonds: electrostatic forces of attraction between oppositely charged cations and anions. Properties of Ionic...
10:37
Protein Complex Affinity Capture from Cryomilled Mammalian Cells
0 Views •
Cited by 37 •
2016
Here we describe protocols to disrupt mammalian cells by solid-state milling at a cryogenic temperature, produce a cell extract from the resulting cell powder, and isolate protein complexes of interest by affinity capture upon antibody-coupled micron-scale paramagnetic beads.
FAQs
The attraction experienced by an incoming electron depends on effective nuclear charge, while atomic radius affects its distance from the nucleus. A stronger effective nuclear attraction can favor electron uptake, whereas a larger radius can weaken that attraction. Comparing these factors helps explain why elements with different positions in the periodic table do not respond identically to added electrons.
Electron configuration can make an atom unusually stable or make the addition of another electron less favorable. Subshell arrangements and existing electron occupancy affect the balance between nuclear attraction and electron-electron repulsion. Consequently, an element may not follow the general periodic pattern, and these deviations provide evidence that configuration stability influences atomic properties.
An incoming electron is attracted to the positively charged nucleus but repelled by electrons already present. The resulting energy change reflects the competition between these forces. Strong nuclear attraction can favor electron addition, while substantial repulsion can reduce that favorability or contribute to energy absorption. This balance explains why electron affinity cannot be predicted from nuclear charge alone.
Chemists compare electron affinity across elements to identify broad changes in their tendency to form negative ions. Effective nuclear charge, atomic radius, and electron configuration provide the factors needed to interpret those changes rather than treating the trend as uniform. Noting configuration-based exceptions produces a more accurate explanation of periodic behavior.
Electron affinity indicates how favorably an atom may accept an electron and become an anion. Comparing this property among elements helps chemists assess tendencies relevant to ionic bonding, alongside the broader behavior of the participating atoms. The comparison is especially useful when periodic trends and unusual electron configurations produce different propensities for negative-ion formation.
Because electron affinity describes an atom’s response to gaining an electron, it provides context for reduction-related behavior in chemistry. Comparing values can help identify differences in the tendency of elements to form anions and can support interpretation of redox patterns. Electron configuration exceptions must still be considered because they may alter the expected reactivity trend.